Water-circulating household appliance with an embossed washing drum

ABSTRACT

The invention relates to a water-circulating household appliance that may be, for example a washing machine, washer-drier, or clothes drier. The household appliance includes a rotatably mounted washing drum with a drum casing and a drum cover face. The washing drum is embossed with protrusions in the form of embossments whose edges are ellipsoidal.

The invention relates to a water-circulating household appliance, for example a washing machine, washer-drier or clothes drier, having a rotatably mounted washing drum with a drum casing and at least one drum cover face, with the washing drum being embossed and the edges of the embossed sections being ellipsoidal. The invention also relates to a washing drum for a water-circulating household appliance with a drum casing and at least one drum cover face, with the washing drum being embossed.

EP 0 935 687 B1 discloses a washing machine or a washer-drier with a rotatably mounted drum which is arranged horizontally or inclined in a lye container. The casing of the drum comprises an arched structure which consists of polygons and is directed toward the interior of the drum. Holes are arranged in the corners of the edge contour of the arched structure.

DE 197 31 666 A1 discloses a washing drum for an electrical clothes drier. The drum casing is embossed in a wavelike fashion.

DE 196 03 710 A1 discloses a water-circulating household appliance, e.g. a washer-drier or a drum-type washing machine, comprising a lye container and a washing drum which is rotatably arranged in the lye container, with the casing of the lye container being embossed. The embossed sections may be round, oval or polygonal. Round embossed sections exhibit a slightly arched form.

DE 44 45 669 A1 discloses a washing drum for a washing machine, which has a plurality of holes across a cylindrical casing in order to allow the passage of working fluid. Trough-shaped indentations and/or elevations are provided between these holes.

DE 101 45 079 C1 discloses a drum for a clothes drier having a perforated drum base as well as a loading opening and a drum casing connected to the drum base. Embossed sections in the form of an arched structure embodied in the manner of a honeycomb are present on the drum cover face, the honeycomb surfaces of which are directed toward the exterior of the drum.

The object of the present invention is therefore to provide a water-circulating household appliance and a washing drum with improved washing and drying characteristics.

This object is achieved by a water-circulating household appliance having the features of claim 1 and a washing drum having the features of claim 18. Advantageous embodiments are the subject matter of the dependent claims.

In an inventive water-circulating household appliance, e.g. washing machine, washer-drier or clothes drier, having a rotatably mounted washing drum with a drum casing and at least one drum cover face, with the washing drum being embossed, the edges of the embossed sections are ellipsoidal. Flow-efficient channel-like cavities form as a result in the non-embossed section of the washing drum. A fluid, which flows in these channel-like cavities between the embossed sections and the clothes resting thereupon, thus has fewer flow losses as a result of the ellipsoidal shape.

The embossed sections are preferably applied to the drum casing. The clothes rest predominantly on the drum casing, so that application of the embossed sections is particularly expedient here.

In a further embodiment, the embossed sections are directed inward in relation to the washing drum.

In a supplementary embodiment, the embossed sections feature a different size and/or a different shape, i.e. such that the ellipses forming the basis of the embossed section have different half-axes a, b. A further adjustment to different ratios can be effected as a result.

In a further embodiment, the large half-axis a has a length of 5 to 15 mm and the small half-axis b a length of 2.5 to 10 mm.

In a supplementary embodiment, the contour of the cross-section of the embossed sections, in particular parallel to the respective axis of the ellipse, is curved or has one or a number of angles, e.g. triangular or rectangular. The shapes of the embossed sections are thus different and can thus be adjusted to different conditions.

In a further embodiment, the curvature in cross-section is irregular and/or the incline of the embossed sections in cross-section is different.

In a supplementary embodiment, the depth of the embossed sections is 0.5 to 5 mm.

In an additional embodiment, the embossed sections are arranged at a minimal distance of 3 to 10 mm for instance from one another. As a result of a minimal distance between the embossed sections, channel-like cavities form, into which detergent and drying air can flow effectively.

The embossed sections are expediently arranged offset from one another in order to be able to apply as many embossed sections per unit of area as possible. More embossed sections per unit of area strengthen the positive effects of the embossed sections in a washing drum.

In a further embodiment, a half-axis a, b, of the ellipse forming the basis of the embossed section is aligned in parallel, at right angles or inclined at a defined angle a toward the drum axis for the embossed sections on the drum cover.

In another embodiment, flow holes are formed in the drum casing, in the case of a washing machine or a washer-drier.

In a supplementary embodiment, flow holes are arranged between the ellipsoidal embossed sections or in the ellipsoidal embossed sections.

The flow holes preferably have a diameter of 1 to 4 mm and the distance between the flow holes is between 2 and 10 mm.

In a further embodiment, the embossed sections are attached to sub-areas of the drum casing.

In a supplementary embodiment, the embossed sections are discontinued and/or not formed at an agitator rib. This ensures that the agitator rib is continuously secured to the drum casing and no dirt or fluff can get into the spaces between the embossed section and the agitator rib.

In a washing drum according to the invention for a water-circulating household appliance having a drum casing and at least one drum cover face, the washing drum is embossed, with the edges of the embossed sections being ellipsoidal.

The invention is described by way of example below, with reference to drawings, in which;

FIG. 1 shows a perspective view of a washing machine according to the invention,

FIG. 2 shows a perspective view of a washing drum according to the invention,

FIG. 3 shows a plan view onto a flat projection of a drum casing,

FIG. 4 shows a plan view onto a flat projection of a drum casing in a further, embodiment

FIG. 5 shows a plan view onto a flat projection of the drum casing in a supplementary embodiment,

FIG. 6 shows a view of an ellipse forming the basis of the embossed section,

FIG. 7 shows a cross-section of a washing drum according to the invention having embossed sections with a square cross-section and

FIG. 8 shows a cross-section of a washing drum according to the invention having embossed sections with an arched cross-section.

FIG. 1 shows a washing machine 1 according to the invention with an inventive washing drum 6. The washing drum 6 according to the invention has a drum cover face 3 and a drum casing 2. The drum casing 2 is embossed 4. The edges of the embossed sections, i.e. the transition between the embossed section 4 and non-embossed section of the washing drum 6, in particular the transition between the embossed section 4 and the non-embossed section of the drum casing 2, is ellipsoidal. Agitator ribs 5 are still also preferably present on the drum casing 2. The embossed sections 4 are directed inward toward the washing drum 6. The embossed sections 4 can however also be directed outward. The shape of the edge of the embossed section 4 does not need to correspond exactly to that of an ellipse in the mathematical sense. The ellipsoidal embossed sections 4 can also have forms which deviate slightly from an ellipse in the mathematical sense. The embossed sections 4 are generally applied to the drum casing 2 both in the case of the washing machine 1 described in the exemplary embodiment or a washer-drier (not shown) as well as in the case of a washer-drier (not shown).

In addition to the same forms illustrated in FIGS. 3, 4 and 5, the embossed sections 4 can also have a different size and/or a different shape. Embossed sections 4 having a different shape are embossed sections in which the ellipses forming the basis of the embossed section have different half-axes a and b (FIG. 6). The large half-axis a normally exhibits a length in the range of approximately 5 to 15 mm and the small half-axis b generally exhibits a length in the range of 2.5 to 10 mm. The cross-section of the embossed sections 4 can be embodied in an arched fashion or can have one or a number of angles. FIG. 7 shows a cross-section with a rectangular cross-section and FIG. 8 shows an embossed section with an arched cross-section. A dome-shaped embossed section 4 results in the case of an arched cross-section of the embossed sections 4. When the cross-section of the ellipsoidal embossed sections 4 has one or a number of angles, e.g. with a triangular or rectangular cross-section of the embossed sections, a cuboid-type form of the embossed section 4 results for instance.

Likewise the curvature radius and/or the incline of the cross-section of the embossed section may be different. In the region of the transition between the embossed section 4 and the non-embossed section of the drum casing 2, a relatively large incline toward the drum casing 2 may be present for instance and on the other hand this incline may decrease slowly in the direction of the center of the ellipsoidal embossed section 4. The depth of the embossed sections lies within a range of approximately 0.1 to 10 mm, preferably in a range of 0.5 to 5 mm.

The embossed sections 4 are preferably arranged at a minimal distance from one another, 1 mm for instance. As a result the water is advantageously able to flow unhindered between the embossed sections 4 during the washing or rinsing process, e.g. to the flow holes 9, which are present in washing machines 1 or washer-driers. In the case of a clothes-drier, an air cushion forms as a result of the intermediate spaces, onto which air cushion the clothes drop in a cushioned fashion, which serves to protect the clothes and also reduces the amount of noise. In a preferred embodiment, the ellipsoidal embossed sections are offset, as shown accordingly in FIGS. 3 to 5. The offset allows more embossed sections 4 to be applied to the drum casing 3 per unit of area, thereby increasing the overall effect of the embossed sections 4.

FIG. 2 shows an inventive washing drum 6 with a drum casing 2 and a drum cover face 3. The washing drum 6 rotates about a drum axis 7 in the direction of rotation 8.

The embossed sections 4 can also be aligned differently on the drum casing 2. FIGS. 3, 4 and 5 show a plan view of the flat projections of the drum casing 2. The embossed sections 4 are each arranged offset in these figures. FIG. 3 shows the large half-axis a of the ellipse forming the basis of the embossed section 4 at right angles to the drum axis 7 and parallel to the direction of rotation 8. The arrangement is shown the other way round in FIG. 4. Here the large half-axis a of the ellipse, which forms the basis of the embossed sections 4, is at a right angle to the direction of rotation 8 and parallel to the drum axis 7. In a further embodiment according to FIG. 5, the large half-axis a of the ellipse, which forms the basis of the ellipsoidal embossed sections 4, is aligned at an angle a to the drum axis 7. In addition, FIGS. 3, 4 and 5 show the cross-section 10 of the embossed sections 4 in the direction of the large half-axis a and the cross-section 11 of the embossed sections 4 in the direction of the small half-axis b.

In the present exemplary embodiment, a washing machine 1 or a washer-drier is described. The flow holes 9 which are generally present here are therefore also shown in FIGS. 3 to 5. The flow holes 9 are preferably positioned between the embossed sections 4 or even in the embossed sections 4 (not shown). The flow holes 9 have a diameter of generally 1 to 4 mm and are arranged at a distance of approximately 2 to 20 mm from one another.

The embossed sections are advantageous in the case of a washing drum in a water-circulating household appliance in that the washing drum is reinforced by them. It is hereby possible to save on material and to achieve a noise reduction as a result of the increased rigidity of the washing drum 6. As a result of the surface structure produced by the embossed sections, scratches or other slight damage to the surface inside the washing drum are barely visible, thereby rendering the washing drum less optically sensitive in an inventive water-circulating household appliance.

Flow channels form between the non-embossed section of the drum casing, because clothes rest on the ellipsoidal embossed sections. In these channels, the water is able to flow unhindered to the flow holes during the washing process. This also applies to rinsing. Furthermore, the water supply is naturally also improved as a result. The embossed sections massage the clothes and in doing so enhance the washing process. The increased surface pressure due to the ellipsoidal embossed sections means that the clothes are agitated better by the washing drum, thereby improving the overall washing process.

An air flow forms between the embossed sections during the drying process, when used in an inventive clothes drier or washer-drier, so that the drying performance can be improved and enhanced as a result. The air cushion present between the embossed sections allows the clothes to drop more gently. The noise produced is thus reduced and the clothes are protected as a result of the cushioned impact on the drum casing. Furthermore, some of the moisture in the clothes can diffuse into this air space and/or the air cushion in this channel-like cavity between the clothes and the embossed sections. Drying performance is hereby enhanced. The supplied drying air can thus absorb the moisture more easily, thereby enhancing drying performance and reducing energy consumption. 

1-19. (canceled)
 20. A drum for imparting movement to items disposed therein while the drum is moved about a drum axis, the drum comprising: a.) a drum casing extending angularly around a drum axis, the drum casing having nominal surfaces extending along a predetermined angular circumference that is at a nominal radial spacing from the drum axis; b.) a drum cover extending radially and located at one axial end of the drum casing, the drum cover and the drum casing together delimiting an interior volume and the drum cover having nominal surfaces extending along a predetermined nominal radial plane and the drum cover having an inward facing cover surface that faces in the axial direction toward the interior volume; and c.) a plurality of protrusions disposed on at least one of the drum casing and the drum cover, each protrusion having a base edge that is generally ellipsoidal in shape and each protrusion protruding inwardly from its base edge toward the interior volume, as viewed relative to the nominal surfaces of the respective one of the drum casing and the drum cover on which the protrusion is disposed, and the protrusions being at a relatively minimal spacing from adjacent other protrusions with the protrusions at this relatively minimal spacing arrangement delimiting channel-like interstitial configurations between adjacent protrusions.
 21. The drum as claimed in claim 20, wherein protrusions are disposed on the drum casing.
 22. The drum as claimed in claim 20, wherein the ellipses delimited by the base edge of one of the protrusions delimits a pair of ellipses each defined relative to an ellipse half-axis and the half-axes of these ellipses are different from the half-axes defining a pair of ellipses of the base edge of another one of the protrusions such that the ellipses of the base edge of the one protrusion have at least one of a different size and a different form than the ellipses of the base edge of the another one of the protrusions.
 23. The drum as claimed in claim 22, wherein the ellipses of the base edge of the one protrusion include a large half axis having a length of 5 to 15 mm and a small axis having a length of 2.5 to 10 mm.
 24. The drum as claimed in claim 20, wherein the contour of the cross-section of the protrusions is a selected one of an ellipsoidal shape, an arched shape, and a shape having at least one angle parallel to an axis of the respective protrusion.
 25. The drum as claimed in claim 24, wherein the contour of the cross-section of the protrusions is a selected one of a triangular shape and a rectangular shape.
 26. The drum as claimed in claim 25, wherein at least one of the curvatures in cross-section of the protrusions is non-uniform and the incline of the protrusions in cross-section is different.
 27. The drum as claimed in claim 20, wherein the depth of the protrusions is 0.5 mm to 5 mm.
 28. The drum as claimed in claim 20, wherein the protrusions are arranged at a minimum distance of 3 mm to 10 mm from one another.
 29. The drum as claimed in claim 20, wherein the protrusions are arranged offset from one another to facilitate the density of protrusions per unit area.
 30. The drum as claimed in claim 20 and further comprising flow holes formed in the drum casing.
 31. The drum as claimed in claim 30, wherein the flow holes are disposed at at least one of between the protrusions and in the protrusions.
 32. The drum as claimed in claim 30, wherein the flow holes each have a diameter of 1 mm to 4 mm and the distance between the flow holes is 2 mm to 10 mm.
 33. The drum as claimed in claim 20, wherein the drum casing includes an axially extending agitator rib and the protrusions are not located on the agitator rib.
 34. The drum as claimed in claim 20, wherein the drum is operable to be rotatably mounted in a water-circulating household appliance.
 35. The drum as claimed in claim 20, wherein the drum is operable to be rotatably mounted in a household appliance that is a selected one of a washing machine, a washer-drier, and a clothes drier.
 36. A washing drum comprising: a drum casing; at least one drum cover face; and embossed sections formed on the washing drum, the embossed sections being directed inward and having ellipsoidal edges and the embossed sections being arranged at a minimum distance from one another, thereby forming channel-like cavities. 